<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*子孙后代选择器*/
        /*body div div p{color: red}*/
        /*子元素选择器*/
        body>div>div>p{color: red}
        /*伪类选择器*/
        /*未访问*/
        a:link{color: red}
        /*访问过*/
        a:visited{color: green}
        /*悬停*/
        a:hover{color: yellow}
        /*激活(点击)*/
        a:active{color: pink}
    </style>
</head>
<body>
<a href="http://www.baidu.com">超链接1</a>
<a href="http://www.qq.com">超链接2</a>
<p>p1</p>
<div>
  <p>p2</p>
</div>
<div>
    <div><p>p3</p></div>
    <div>
        <p>p4</p>
        <div><p>p5</p></div>
    </div>
</div>
</body>
</html>